Austrian Pat. No. AT-PS 357,430 describes a lock cylinder having a cylinder housing and a cylinder core having at least one, and usually a plurality, of rotatable magnetic tumblers or rotors supported therein.
In the cylinder core at least one axially slidable locking element is also provided and has its axial position controlled by the rotatable magnetic tumblers. The locking element has at least one projection, preferably a plurality of projections, directed toward the exterior of the lock cylinder.
The inside or inner wall of the cylinder housing has at least one circular groove and a longitudinal groove, the circular grooves being so located axially that in the axially advanced position of the locking element, in which contacting elements protruding toward the inside of the lock cylinder lie in notches of the rotatable magnetic tumblers, a release of the restrained projections of the locking element allowing rotation of the cylinder core is provided.
We have found it to be desirable to reduce the forces operating during faulty or incorrect locking on the rotatable magnetic tumblers of the lock cylinder, in order to prevent possible damage to the rotatable magnetic tumblers, and to enable a reduction in the dimensions for the contacting elements and other components and thus to increase the mechanical precision of the lock. Furthermore it is also desirable to reduce the influence of the environment, including that of weather, dust, corrosive material, and the like on the circular lock, and on the components found moving on the inside of the cylinder core.